Use of minimally invasive procedures, such as catheter ablation, to treat a variety of heart conditions, such as supraventricular and ventricular arrhythmias, is becoming increasingly more prevalent. Such procedures involve the mapping of electrical activity in the heart (e.g., based on cardiac signals), such as at various locations on the endocardium surface (“cardiac mapping”), to identify the site of origin of the arrhythmia followed by a targeted ablation of the site. To perform such cardiac mapping a catheter with one or more electrodes can be inserted into the patient's heart chamber.
Under some circumstances, the location of the catheter in the heart chamber is determined using a tracking system. Catheter tracking is a core functionality of modern mapping systems that also include software and graphic user interface to project electrical data on 3D renderings of cardiac chambers. Currently there are several tracking systems available, some more useful and commonly used than others. Some systems are based on the use of magnetic or electric fields from external sources to sense and track the location of the catheter. Some are based on the use of magnetic or electric fields sources mounted on the tracked catheters.